Avalanche Forecast

Archived

Feb 4th, 2023–Feb 5th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Northwest Inland, Kispiox, Microwave-Sinclair, Ningunsaw, South Bulkley, South Bulkley, Telkwa.

Carefully assess for wind slabs as you gain elevation. Wind slabs will likely remain rider triggerable due to the underlying surfaces.

Confidence

Moderate

Avalanche Summary

A few new small natural and human triggered wind slab and loose dry avalanches have been reported in the region over the past couple days.

Larger avalanches on more deeply buried persistent weak layers were reported last week during a warm spell, like this one in the Telkwa area . Persistent problems like this one will be slow to change and improve.

If you are out in the backcountry please consider filling out a Mountain Information Network report.

Snowpack Summary

Ongoing snowfall over recent days has accumulated around 40 cm of fresh snow that is being blown into wind slabs by southwest winds. This all sits on a crust from the warming event on January 25th. New snow likely will not bond well to this crust.

The mid and lower snowpack continues to bond and stabilize. A few concerning weak layers can still be found in the top meter of the snowpack including a surface hoar layer from early January and a crust from late December.

Weather Summary

Saturday Night

light flurries bringing a few centimeters of new snow. Moderate to strong southerly winds and a above freezing layer around 1500m.

Sunday

A mix of sun and cloud with flurries bringing trace amounts of new snow. Moderate to strong westerly winds and temperatures at 1500m around -3.

Monday

Increasing cloud throughout the day with up to 5cm of new snow expected. Strong southwest winds and freezing levels rising to 1800m.

Tuesday

Mostly cloudy with the possibility of light flurries bringing trace amounts of new snow. Light variable winds and freezing levels falling to valley bottom.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Wind slabs are most reactive during their formation.
Wind slabs may be poorly bonded to the underlying crust.
Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.